Researchers primarily from the University of Maryland

Researchers primarily from the University of Maryland, along with Google, have created a new tool to help scientists monitor forest disturbance. The researchers have synthesized 12 years' worth of satellite imagery into a maplike interactive tool illustrating recent changes in the extent of forest cover around the world. Their findings were published Thursday in the journal Science.Can This Tool Predict Your Next Facebook Status? By providing a record of changes in forested areas across the globe, the tool can be used to help track threats to biodiversity, the effectiveness of policies that protect forest areas and the release of carbon long tied up in trees and other organic material, among other forest health issues.Trees absorb carbon dioxide for use in photosynthesis, making them one of the most effective natural tools to remove the greenhouse gas from the atmosphere.

The map includes any area that charted gains or losses in forest cover during the observed period. Areas that experienced no change in the amount of forest cover are shown as blacked out.More than 650,000 Landsat satellite images taken between 2000 and 2012 were drawn on to create the map. By some estimates, it could have taken a lone computer 15 years to process that volume of data, but because of Google's involvement it took just a few days, said Matthew Hansen, a professor of geographical sciences at the University of Maryland and the study's lead author. Still, he said, even with its enormous processing power, Google's servers broke a sweat.

"When they ran it, the lights dimmed," Dr. Hansen said.Previous efforts at forest mapping have been at very coarse resolutions, he said. With a spatial resolution of 30 meters almost 33 yards, the map stands as the most visually refined tool of its kind."At 30 meters you start to see things a lot more clearly," Dr. Hansen said.At that resolution, he said, the tool can be used to help shape deforestation policy, even on a local scale. Still, despite an interface much like Google Maps — the resource was developed using the Google Earth Engine platform — the interactive graphic doesn't zoom down to individual stands of trees, for instance, the way a pastiche of satellite images might. Rather, it illustrates changes in land character using color blocking.